Method and apparatus for removing entrained matter from centrifugal filter media

ABSTRACT

A method and apparatus for removing solid and liquid material entrained in the filter media of a centrifugal aerosol filtering system by periodically spraying a sufficient quantity of a solubilizing solution on the filter media to solubilize the entrained material thereby allowing it to pass through the filter media.

limited States Patent [191 Horn et a1.

[ METHOD AND APPARATUS FOR REMOVING ENTRAINED MATTER FROM CENTRIFUGALFILTER MEDIA [75] A Inventors: Edward A. Horn; Irwin Miness;

Henry R. Roster], all of New York,

[73] Assignee: Chemical Detergents C0.,Inc.,

New York, N.Y.

22 Filed: June 11,1971

[21] App]. No.: 148,606

[52] US. C1..- 55/96, 55/97, 55/227,

55/233, 55/242, 55/400 [51] lint. Cl lB0ld 33/02 [58] Field of Search55/84, 87, 90, 91,

. 55/96, 97, 227, 233, 228, 242, 400, 524; 252/524, 529, 539, DIG. 14;210/59, 60, 403

[56] References Cited UNITED STATES PATENTS 1,717,412 6/1929 Rowe 55/2271,814,864 7/1931 Sinclair. 162/279 2,018,938 10/1935 Wells 162/53,239,863 3/1966 Gardner... 101/425 3,265,625, 8/1966 Grob 252/D1G. 143,281,367 10/1966 Jones et a1. 252/D1G. 14

[ Oct. 9, 11973 3,289,397 12/1966 Schonewald et al.- 55/400 3,385,5735/1968 Gilman 55/233 3,494,108 2/1970 Moragne 55/227 3,589,609 6/1971Wyant et a1. 55/227 3,242,652 3/1966 Malenchini 55/228 3,395,901 8/1968Moser 55/233 FOREIGN PATENTS OR APPLICATIONS 867,343 2/1953 Germany55/408 393,117 6/1933 Great Britain 55/231 OTHER PUBLICATIONSInstruction Bulletin Dynopure Ink Mist Filter System, Goss C0., ChicagoIllinois dated July 1967, pages 14.

Primary Examiner-Bernard Nozick At t0rneyMcLean, Boustead and Sayre [57]ABSTRACT A method and apparatus for removing solid and liquid materialentrained in the filter media of a centrifugal aerosol filtering systemby periodically spraying a sufficient quantity of a solubilizingsolution on the filter media to solubilize the entrained materialthereby a1- lowing it to pass through the filter media.

4 Claims, 2 Drawing Figures PATENIEB URI 91975 SHEET 10F 2 WIN M N NRYRROSTEN INVENIORS D R A WR I E ATTORNEYS PAIENIEU B W3 3. 763.631

sum 2 [IF 2 CONTROL BO INVENTORS ATTORNEYS METHOD AND APPARATUS FORREMGVTNG ENTRAINED MATTER FROM CENTRTFUGAL FILTER MEDIA v BACKGROUND OFTHE INVENTION 1. Field of the Invention The invention relates to amethod and apparatus for removing entrained material, both solid andliquid, from the filtering media of a centrifugal pressure differentialfilter system utilizing a sufficient quantity of a solubilizing solutionsprayed onto the rotating filter media to solubilize the solid material,thereby allowing it to pass-completely through the filter media and beremoved.

The invention has application wherever the solubilizing effect of asolution can be brought to bear on entrained particulate matter throughthe action of the centrifugal force of the rotating filter media and thecentrifugal force can further act on the solubilized matter to force itthrough and out of the filter media.

2. Description, of the Prior Art in recent yearsconsiderable investmentsof time and money have been made in attempts to clean up industrialworking environments, particularly with respect to the airbornepollutants or contaminants that are produced as a result of variousindustrial operations. These airborne pollutants often appear asaerosols in the form of smoke, fog or mists comprised of minute solid orliquid particles.

The printing industry, and in particular'newspaper printing plants, havefound it necessary to install air exhaust and filter systems not only toimprove the working environment of the pressroom personnel, but tomaintain the quality and appearance of the product and to .avoidaccumulations of ink mist on other materials or equipment, the removaler which present major housekeeping problems. The type of ink used innewspaper printing is comprised of mineral oil, rosins and/or resins,carbon black and color pigments or dyes.

Obviously, the most efficient method of keeping the industrialenvironment free of this form of contaminant is to capture theaerosol-laden air as close as possible to its source of production as bymeans of an exhaust or vacuum system and carry it away. In earlier timesit might have seemed practical to simply discharge this exhaust streaminto the atmosphere, but ecological considerations now militateagainstthis means of disposing of the aerosolladen stream. Various types ofmechanical filtering systems and electrostatic precipitators have beendeveloped and are currently being used in industrial facilities toremove the suspended particles in exhaust air streams.

One particular type ofapparatus that has been found useful in theprintingindustry to remove the objectionable ink mists which aregenerated during the highspeed printing process is vthe' centrifugalfiltering system. The system is comprised ofa number of closed ducts inwhicha low pressure is maintained relative to ambient pressure in thevicinity of the press plates and blanket rolls. These ducts are securedto mist guard plates or shields which effectivelyenclose the printingpresses, the ducts having a number of perforations or intake manifoldscommunicating with the interior airspace immediately adjacent to theprinting plates. The other end of these collecting ducts communicatewith means for producing the low pressure in the system.

A cylindrical perforated rotating drum containing a lining of filteringmedia is interposed between the open or collecting end of the duct andthe lower pressure producing means. The aerosol-laden air stream fromthe vicinity of the presses enters the rotating filter assembly axiallythrough the inletduct and is centripetally accelerated towards thefilter media. As the particles which form the aerosol pass through thefiltering media there takes place a coalescing and merging of theparticles to form droplets. These larger droplets are forced through thefilter media and perforated drum and impinge upon an outer stationarycylindrical housing, thereupon settling under the influence of gravity,to the lowest point where the now liquid stream is collected. A morecomplete description of the construction and operation of this type ofcentrifugal filtering apparatus is to be found in U.S. Pat. No.3,289,397, issued on Dec. 6, i966 to Shonewald et al.

Ideally, the centrifugal filter media should be almost self-cleaning ifthe drum and filter media are permitted to rotate while a quantity ofrelatively clean purging air is drawn through the system. A morethorough cleaning of the filter media is accomplished periodically byremoving it from the drum and soaking it in a solvent.

However, when these units were installed on newspaper presses it wasfound that the efficiency of the unit decreased at a much greater ratethan had been estimated, i.e., the vacuum attained after a short periodof operation was low, and also bearing assemblies of the rotating drumshaft wore extremely rapidly due to the out-of-balance condition of thedrum resulting from dried accumulated material at'the low point of drumwhen the device was shut down.

Attempts to eliminate these deficiencies in installed systems centeredaround the use of mineral or organic solvents to dissolve theaccumulated dried ink, but in addition to being ineffective, thesesolvents presented a serious fire hazard not only within the unit itselfbut through the emission of solvent vapors into the general work area.

SUMMARY OF THE INVENTION y We have found that when the centrifugalfilter system is installed forthe collection of ink mists in thevicinity of-high speed printing presses, particularly those used for theprinting of newspapers, an appreciable amount of paper dust" orcellulosic fibers are drawn into the collection manifolds.

When these cellulosic fibers are drawn into the centrifugal filtersystem they become coated with the ink mist, and it has been furtherfound that within a relatively short period of time these coatedcellulosic fibers become entrained in the filter media so as to reducethe porosity thereof, especially at the inner surface, and as the systemcontinues in operation a layer or mat of cellulosic material andthickened ink builds up on this surface of the rotating'filter media.The presence of, this cellulosic material is not immediately apparentbecause of the minuteness of the individual particles and the fact thatthey are completely saturated with an oily coating of ink.

The method and apparatus of the present invention eliminates theproblems of rapidly declining filter porosity and compaction due to thisentrained solid particulate matter by the periodic application ofasuitable solubilizing agent to the filter media while the centrifugalfilter apparatus is operating. This operation is carried out while theapparatus is operating to take advantage of the centrifugal and pressuredifferential forces which are developed therein.

The apparatus provides for an automated spray cleaning system utilizingthis specialized solubilizing agent for periodically cleaning thesefilters, eliminating the necessity of disassembly of the unit,increasing the life of the filter media, retaining the unit in balance,reducing mechanical failure, and maintaining the collection systemwithin its operational design levels. In addition, the apparatus of theinvention provides for the pressurized spraying of a measured quantityof the solu- -bilizing agent at pre-determined intervals and only whilethe centrifugal filter unit is in operation. The solubilizing agent mustbe one that can first penetrate or remove the ink coating on thecellulosic matter, and then act on the cellulosic fibers to effectivelydissolve them so that they are able to pass through the filter media andimpinge on the stationary housing.

We have found that a solution of water and certain surface activeagents, or surfactants, have the requisite physical properties foraccomplishing the penetration or solubilizing of the ink coating and thesubsequent solubilizing of the cellulosic fibers. Particularlysatisfactory surfactant formulations for removing the ink coating andsolubilizing the fibrous cellulosic material are those prepared fromcomplex phosphates, together with an amine condensate of the fatty acidalkanolamide type, and a hydrotropic solubilizing agent in an aqueoussolution.

The complex phosphates can be the sodium or potassium salts oftripolyphosphates, pyrophosphates, metaphosphates, tetraphosphates, ormixtures thereof. In addition to serving as wetting, solubilizing anddispersing agents, these salts form water soluble complexes with calciumand magnesium ions found in hard water and prevent the formation ofinsoluble salts which would tend to precipitate and thereby causeclogging of the spray nozzle. The amine condensate is that of thecoconut fatty acid or the refined fraction of coconut oil or fatty acid(the socalled Kritchevsky condensate of a C ,C fatty acid) with analkanolamine, such as ethanolamine, propanolamine, diethanolamine andthe like; these are mixtures of alkanolamides with alkanolamine soaps offatty acids; or the so-called super amides which are the alkanolamidesin combination with alkanolamine soap. These compounds serve as foamboosters and toincrease the viscosity and emolliency of the aqueoussolution. The hydrotropic solubilizing agents can be the sodium,potassium or ammonium salts of toluene sulfonic acid, xylene sulfonicacid or benzene sulfonic acid, or mixtures thereof. The hydrotropes areused to solubilize the other ingredients in the concentrated aqueousfonnulation. Preferably, the formation comprises from about 2 percent toabout 10 percent of the complex phosphate, and about 5 percent to about15 percent of the amine condensate of the fatty acid alkanolamide typewith from about 2 percent to about percent of the hydrotrope, all of theabove percentages based on weight, and the balance of the fonnulationbeing made up of water.

In addition to the aqueous medium provided in preparing the surfactantformulation an additional quantity of water must he added to prepare thesolubilizing solution. Satisfactory results can be obtained using ratiosof about four to about six to one of water to surfactant formulation,with a ratio of about five to one being preferred for the solubilizationof cellulosic material in the black ink mist filtering system. In theactual practice of the invention in industrial applications the leastexpense will be incurred by shipping the surfactant formulation only inappropriate containers with the preparation of the solubilizing solutionby addition of the required quantity of water being accomplished at thesite of use.

While the above formulation has been found to be particularly effectiveas a solubilizing agent when mixed with additional quantities of water,other formulations can be prepared and utilized so long as they canfirst penetrate or remove the ink coating on the cellulosic matter andthen act on the cellulosic fibers to effectively dissolve them so thatthey are able to pass through the filter media and impinge on thestationary housing.

Utilizing the method and apparatus of the invention it is unnecessary toshut down the centrifugal filter apparatus and remove the filter mediafor cleaning or replacement in order to maintain the efficiency of thefiltering system at acceptable levels. Thus, conventional methods ofcleaning the filter media, as by soaking in organic solvents andmechanical agitation which were incapable of removing the deeplyentrained and matted cellulosic fibers are obviated, and the expense ofmaintenance as measured in terms of down time, material and labor costswill be greatly reduced.

In addition to maintaining the efficiency of the collection system, theperiodic application of the solubilizing solution prevents the formationof deposits of condensed fluids which settle at the lowest point whenthe filter is idle, as at the end of a production run, and which causesevere vibrations upon restarting. Eliminating this vibration avoidsdamage to the drive motor bearings and avoids costly overhaul and partsreplacement associated with mechanical failure that has been experiencedin the past.

Under actual operating conditions, utilizing the methods and apparatusof the invention in conjunction with centrifugal filter units in anewspaper printing plant, it was found collection and filtering systemscould be operated at near optimum conditions for over five times longerthan other units installed on black ink presses without removing thefilter media for manual cleaning. Furthermore, these tests indicate thatuse of the method and apparatus of the invention will avoid thenecessity of the manual cleaning operation throughout the life of thefilter media. In addition to maintaining the filter media free ofentrained matter, the periodic application of the solution in accordancewith the method of our invention prevents accumulations of ink-mist andcellulosic matter on the other rotating members comprising the filterunit, on the surrounding stationary drum, and, as a result of keepingthe stream of aerosol moving at design velocities, in the manifolds andconnecting ducts. When the method and apparatus was used on centrifugalfilter units installed on color presses where the ink is comprised ofvarnish or shellac, mineral oil, resins, pigments and dyes, muchimproved filter efficiency was also found.

Thus, the object of this invention is to provide a method and apparatusfor easily and efficiently removing solid matter entrained in thefiltering media of a centrifugal filter.

In particular, the object of this invention is to provide a method andapparatus for removing cellulosic fibers and particles which are coatedwith liquid printing ink, which fibers and particles are entrained inthe filter media of an apparatus that forms a part of an ink-mist filtersystem for use in conjunction with high speed printing press units.

A further object is to provide a method and apparatus whereby theoverall operating life of the centrifugal filter apparatus can beprolonged by preventing the formation of an unbalanced condition in therotating filter assembly and thereby avoiding rapid wear and breakdownof the bearings from tortional strain.

A still further object of this invention is to provide a method andapparatus for removing entrained matter from the filter media which doesnot involve the shutting down of the centrifugal filter apparatus andthe removal of the filter media.

An additional object of this invention is to provide a method andapparatus for treating the filter media that will permit the centrifugalfilter apparatus to operate at close to designed efficiency forprolonged periods in collecting and removing from an aerosol streamsmall particles ofcellulosic material and ink.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings in whichlike reference numbers are used to identify the same parts appearing inthe several figures:-

FIG. I is a side elevational view partly 'in section showing a preferredembodiment of the invention;

7 FIG. 2 is a schematic View of the major components of the apparatuscomprising the invention used in conjunction with a number ofcentrifugal filter units.

In FIG. 11 there is illustrated a centrifugal filter unit 1, which iscomprised of the stationary cylindrical housing 5, with drain tube 7 andoutlet duct 9. Affixed to housing '5 is drive motor6 which drives shaft4 to which perforated rotating drum'2 and pressure differentialproducing means 11 are attached. Porous filter media 3, shown disposedon the inner surface of said rotating drum 2, is typically a foamedplastic, such as polyurethane, or of dacron or pre-shrunk cotton, whichare porous, resilient and flexible; Stationary housing 5 is closed byremovable end cover 8 with inlet duct 10 centrally located therein.Pressure'differential producing means 11 is typically a squirrelcage-type fan which draws the aerosol laden stream in through duct 10axially and causes it to be dispelled through the rotating drum2 andfilter media 3 where the soil and solubilizing liquid arecollected intodrain tube 7 and the air is exhausted through outlet duct 9.

Communicating with the interior of filter unit 1, is nozzle 20, which isdisposed radially from the axis of the rotating drum and outside theperiphery of the opening of inletduct 10 in the end cover 8. It isdesirable to position nozzle" out of the line of the axial flow of theaerosolstream entering through inlet duct 10 to avoid the excessiveaccumulation of material on the nozzle and lead-in assemblyduring'operation and the possibility of this accumulation falling ontothe filter media when the unit is shut down. The use of a slotted-typenozzle fitting in which the orifice is slightly receased is preferred toavoid the build-up and clogging of the nozzle tip bymaterial in theaerosol stream. Nozzle 20 must be disposed so that the spray .emanatingtherefrom will cover all of the inner surfaces of the rotating drum 2and filter media 3 during operation. This will also provide for thespraying of fan means 11.

Nozzle 20 is connected to conduit 25 which in turn communicates with asource of pressurized solubilizing solution in container 30. interposedin line 25, adjacent nozzle 20 is solenoid valve 21, which is normallyclosed.

Solenoid valve 20 is shown connected through relay 22, to timer control23. Relay 22 is connected to motor 6 to insure that solenoid 21 will notbe activated except while filter unit 1 is in operation.

Timer control 23, which may be of any suitable type well-known in theart, may be variably set both with respect to the frequency of thespraying operation and the duration thereof. The duration of the spray,of course, determines the quantity of solubilizing solution which issprayed onto the filter media. These time factors will generally bedetermined by the actual operating conditions and the type of equipmentthat the apparatus is used with. Parameters that will effect thequantity of solution required during each spraying operation are theporosity, density and thickness of the filtering material, theconcentration of matter, especially cellulosic material, in the aerosolstream, and the time lapsed between spraying operations. During anexperimental test of the invention in conjunction with a centrifugalfilter system on high-speed newspaper printing presses it was found thata spray discharge of about three ounces of solubilizing solution every45 minutes was adequate to keep the filter media free of accumulatedmaterial.

As shown in FIG. 2 pressure tank 30 is connected by line 33 to fluidproportioner 45, which in turn is connected through solenoid'valve 41 towater line 42 and also to suction inlet tube 46. Proportioner 45 is ofthe venturi suction type wherein the flow of pressurized water creates asuction at the inlet tube 46 to draw and mix with the water stream theconcentrated solubilizing agent from resevoir 40, which istypically ashipping drum. Pressure tank 30 is connected by line 25 through solenoidvalves 21 to spray nozzles 20 which communicate with the interior ofcentrifugal filter units 1. The pressure tank is also connected byline38, through double acting solenoid valve 36 to vent tube 39 and pressureregulating valve 27. Shipping drum 40 is fitted with low-level fluidsensing device 51, and pressure tank 30 is fitted'with high and lowlevel fluid sensing device 31, and pressure switch 32.

Solenoid valves 36 and 41, pressure switch 32, and fluid level sensingdevices 31 and 51 are connected by appropriate circuitry to control box50, as is timer 23.

The sequence of operations of theappara tus shown in the figures iscontrolled by 'a-number of standard relays interconnected byconventional means and which are contained in the control box 50. i

The following sequence of events will serve as an il lustrat ive exampleof the functioning of the automated system for resupplying solubilizingsolution to the pressure tank 30 when it has been emptied during normaloperations. When fluid low-level sensing device 31 indicates that thefluid in tank 30 has dropped below 'a predetermined level a relay incontrol box 50 opens the circuit to timer- 23, activates double actingsolenoid valve 36 to open line 38 to vent tube 39 thereby cutting offthe source of pressurized air from regulator 27 and releasing thepressurized air from tank 30. When the air pressure in tank 30 reachesatmospheric pressure switch 32 closes to a relay in control box 50 whichin turn opens solenoid valve 41 to plant water line 42. The

stream of pressurized water passing through proportioner 45 drawssolubilizing agent from drum 40 which is introduced into tank 30 throughline 33. When the fluid in tank 30 reaches a predetermined point on highlevel sensing device 31, a signal is transmitted to a relay in controlbox 50 which closes solenoid valve 41, activates solenoid 36 closingline to vent tube 39 and opening line 38 to pressurized air line 26through regulator 27. When the pressure in tank 30 has reached thepredetermined operating level, pressure switch 32 opens and a relay incontrol box 50 reactivates the timer 23. The system is then in conditionfor the next programmed spraying operation as determined by the timer23.

In addition to the above described connections, the low leval sensingdevice 51 in drum 40 is connected to appropriate signalling means, suchas a light or audible alarm which can be conveniently located in controlbox 50 to alert operating personnel that the fluid drum 40 has reachedthe predetermined level and that the drum 40 should be replenished orreplaced with a full drum. The system is automatically shut down untilreplenishment-or replacement with a full drum is accomplished.

We claim:

1. In a centrifugal filtering unit which comprises a stationary housing,a rotatable perforated cylindrical drum having one open end, axiallymounted within the housing, motor means for rotating the drum, acylindrical porous filtering media interior of, and supported by thedrum, an axial inlet duct connected to the housing and communicatingwith the interior of the open end of the drum and housing through whichinlet duct a gaseous stream containing liquid aerosol particles andfinely divided cellulosic material is introduced into the open end ofthe rotating drum, gas outlet means for discharging the filtered stream,and means for collecting the material removed from the gaseous stream,the improvement comprising spray means communicating with the interiorof said stationary housing and the inner surface of the filter media forapplying a spray of solubilizing solution to the interior surface of thefilter media, the spray means being displaced radially from theperiphery of the axial inlet duct, and substantially out of the path offlow of the incoming gaseous stream, means for periodically delivering aquantity of the solubilizing solution to the spray means comprisingelectrically activated valve means and timer control means, and meansfor delivering pressurized solubilizing solution to said valve meanscomprising a closed vessel having inlet and outlet means, high and lowlevel liquid sensing means, means for reducing the pressure in thevessel to atmospheric pressure, and means responsive to the high and lowlevel sensing means and the pressure sensing means for introducing intothe vessel a proportioned stream ofliquids and a stream of pressurizedgas.

2. In the method of removing suspended fine solid and liquid particulatematerials from a gaseous stream comprising drawing the particulatecontaining gaseous stream through an axial inlet duct at one end of astationary housing, and passing the gaseous stream through a supportedcylindrical porous filter media from the interior to the exterioraxially rotated within the housing whereby the particulate materials areentrained in the filter media, and discharging the filtered gaseousstream through an outlet in the housing, the improvement which comprisesspraying the interior surface of the filter media with a solubilizingsolution of water and a surfactant formulation comprised of from about 2percent to about l0 percent of a complex phosphate, from about 5 percentto about l5 percent of an amine condensate of a refined fraction ofcoconut fatty acids having from twelve to eighteen carbon atoms with analkanolamine and from about 2 percent to about 10 percent of ahydrotropic agent, where all percentages are by weight and the balanceof the formulation is water, said solubilizing solution being sprayedfrom a position out of the flow of the incoming gaseous stream and in aquantity sufficient to dissolve and solubilize the entrained materialwhich solution and dissolved material then passes through the filtermedia under the combined effects of the centrifugal acceleration forcesand the pressure differential across the filter media.

3. The method of claim 2 where the surfactant formulation is comprisedof from about 2 percent to about 10 percent of a complex phosphateselected from the group consisting of the sodium or potassium salts oftripolyphosphates, pyrophosphates, metaphosphates, and tetraphosphates;from about 5 percent to about l5 percent of an amine condensate of theKritchevsky type with a refined fraction of coconut fatty acids having12 to 18 carbon atoms where the amine is selected from the group ofalkanolamines consisting of ethanolamine, propanolamine anddiethanolamine; and from about 2 percent to about 10 percent of ahydrotropic agent selected from the group consisting of the sodium,potassium or ammonium salts of toluene sulfonic acid, and benzenesulfonic acid, where all percentages are by weight and the balance ofthe formulation is water.

4. The method of claim 3 where the complex phosphate is sodiumtripolyphosphate, the amine condensate is a diethanolamine condensate ofthe Kritchcvsky type with a refined fraction of coconut fatty acidshaving 12 to 14 carbon atoms, and the hydrotropic agent is sodium xylenesulfonate.

2. In the method of removing suspended fine solid and liquid particulatematerials from a gaseous stream comprising drawing the particulatecontaining gaseous stream through an axial inlet duct at one end of astationary housing, and passing the gaseous stream through a supportedcylindrical porous filter media from the interior to the exterioraxially rotated within the housing whereby the particulate materials areentrained in the filter media, and discharging the filtered gaseousstream through an outlet in the housing, the improvement which comprisesspraying the interior surface of the filter media with a solubilizingsolution of water and a surfactant formulation comprised of from about 2percent to about 10 percent of a complex phosphate, from about 5 percentto about 15 percent of an amine condensate of a refined fraction ofcoconut fatty acids having from twelve to eighteen carbon atoms with analkanolamine and from about 2 percent to about 10 percent of ahydrotropic agent, where all percentages are by weight and the balanceof the formulation is water, said solubilizing solution being sprayedfrom a position out of the flow of the incoming gaseous stream and in aquantity sufficient to dissolve and solubilize the entrained materialwhich solution and dissolved material then passes through the filtermedia under the combined effects of the centrifugal acceleration forcesand the pressure differential across the filter media.
 3. The method ofclaim 2 where the surfactant formulation is comprised of from about 2percent to about 10 percent of a complex phosphate selected from thegroup consisting of the sodium or potassium salts of tripolyphosphates,pyrophosphates, metaphosphates, and tetraphosphates; from about 5percent to about 15 percent of an amine condensate of the Kritchevskytype with a refined fraction of coconut fatty acids having 12 to 18carbon atoms where the amine is selected from the group of alkanolaminesconsisting of ethanolamine, propanolamine and diethanolamine; and fromabout 2 percent to about 10 percent of a hydrotropic agent selected fromthe group consisting of the sodium, potassium or ammonium salts oftoluene sulfonic acid, and benzene sulfonic acid, where all percentagesare by weight and the balance of the formulation is water.
 4. The methodof claim 3 where the complex phosphate is sodium tripolyphosphate, theamine condensate is a diethanolamine condensate of the Kritchevsky typewith a refined fraction of coconut fatty acids having 12 to 14 carbonatoms, and the hydrotropic agent is sodium xylene sulfonate.